The Blues had plenty of chances, but only prevailed when Willian curled in a decisive second, following another assist by Eden Hazard, who was again deployed as Chelsea's 'false nine'.

Goalscoring remains an issue for Chelsea, who faced the prospect of a third top-flight home game without scoring for the first time since November 1993, but finished the day with a six-point advantage over fifth-placed Arsenal, who lost 1-0 at West Ham.

But Cathcart made amends in the 67th minute when he scored at the other end to level and seven minutes later Tom Cleverley smashed a loose ball into the top corner to set Watford on their way to a 2-1 victory.